Graphics and text are typically applied to the exterior of packaging for consumer products in order to communicate information to the consumer, such as brand, advertising, promotional or product information. In addition, machine readable indicia, such as bar codes, are commonly applied to the exterior of the packaging to provide information, such as the price of the product. This machine readable information may be read using a scanner or other suitable reader at the point of sale, or during distribution of the products. Typically, consumer information applied to the packaging does not change during the period of time between printing of the packaging and sale of the products. However, information encoded in the machine readable indicia may change during this period. In particular, the price of the products may vary over time and may also alter depending upon the retail outlet in which the products are being sold. When such information changes, large quantities of packaged consumer products may already exist with machine readable indicia encoded with incorrect or outdated information. The machine readable indicia on the existing packaged goods must be covered and replaced with new indicia, for example using an adhesive label printed with the new indicia, or the packaging discarded, with or without the products inside.
It would be desirable to be able to apply machine readable indicia, in particular bar codes, to the packaging of consumer products in such a way that the indicia may be readily updated or replaced when the information encoded by the machine readable indicia changes.